Extension-ladder



(No Model.) a sheets-sheet 1.

J. L. CRAFTS. Extension Ladder.

No. 242,114. Patented May 31, I881.

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(N 0 Model.) 8 Sheets-Sheet 2.

J. L. CRAFTS. Extension Ladder. Ng. 242,114. Patented May 31, 1881..

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Extension- Ladder.

No. 242,114. Patented May 31, I881.

'tains to make and use the same.

PATENT ()FFIcE.

JOHN L. CRAFTS, on S'oMnnVILLE, MAssAonUSETTS.

EXTENSION-LADDER.

SPECIFICATION forming part of Letters Patent No. 242,114, dated May 31,1881.

Application filed June 10,1880. (N6 model.)

To all whom it may concern: y Be it known that I, JOHN L. CRAFTS, acitizen of the United States, residing at Somerf ville, in the county ofMiddlesex, State of Mas-.1 sachusetts, haveiuvented certain newImprovements in Extension-Ladders; and I hereby de-; clare the followingto be a full, clear, and exactl description of the invention, such aswill enable others skilled in the art to which it apper-f This inventionrelates to extension lad-g ders, so called-that is, ladders capable ofexpansion and contraction in the direction of f their length, andadapted for firemens use in extinguishing fires or for other purposes.

Minor details of my improvements will bej duly explained hereinafter.

The drawings accompanying this specifica-l tion represent, in Figure 1,a central vertical! longitudinal section of my ladder Figs. 2 andi 3,central vertical longitudinal sections of rearf and front endsrespectively, while Figs. 4 and? 5 are plans of the front and rear endsof thej same ladder. Fig. 6 is a side elevation of ladder in erectposition and ready for use. p

In the above-named drawings, A represents a truck of a size and form toadapt it to they purpose of supporting a heavy ladder, such" truck beingcomposed of a rectangular framej B, mounted upon axles and wheels 0 Gand} D D D D, and provided with a pole for attachment of thedraft-horses, a brake, E, being combined with the hind wheels, D D, toprevent movement of the truck while the lad der is erected.

Upon the rear part of the truck-frame I erect a standard or frame, E,composed of two triangular-shaped housings, F F, connected with? thetruck by a transverse horizontal pivot, (if in such manner that thestandard may be turned upon such pivot and lowered into a horizontalposition, in which event its free end overhangs the rear ends of thetruck, and,'in conjunction with a horizontal cross bar or roller, 11,mounted in standards 0 c erected upon the front end of thetruck,constitutes a long and efficient bearing for the ladder when thelatter is folded and lowered into the position it occupies when not inuse. When in its lowered position the rear or longer side, 01, of thestandard E rests upon the rear end of the truck, and, in conjunctionwith this bearing and its own pivot, serves to i uphold the greater partof the weight of the ladder, the forward end of the ladder at such timeresting upon the roller b, before named. When the standard E is in anupright position its shorter side or base 0 rests upon the top of thetruck and serves to support the weight of the ladder as it is beingraised or lowered in a contracted state, or while being extended orcontracted in length after being raised.

The main portion or section of the ladder is shown at G as composed oftwo pairs of rails, H H H H, all united by the rungs or rounds ff, 860.,the inner rails, H H, serving not only to greatly stiffen and strengthenthe main section of the ladder, but as a support, each for i a metallicplate or bar, I I, which is secured to its outer face, each plate Ioverhanging the inner edge of the rail, as shown at 9, while beneath orinside each of these plates is a lug, h,

extending laterally from the lower end of the sliding or extensionsection J of the ladder. As the section J is raised or lowered the lugsh h slide beneath the plate or guides I, and

i serve to insure connection of the two sections of the ladder. The mainsection of the ladder is provided with suitable side trusses, L L, andit is pivoted at about one-third its length from its lower end, by ahorizontal rod or pivot, i, to the upper part of the standard E ,in suchmanner as to be capable of swinging upon the latter.

The rails of the sliding or extension section of the ladder areshown atN N, and its rounds at K K, &c;, and its said rails N N are providedwith trusses l I, after the manner of the main section.

The lower end of the extension J is confined to the main portion of theladder by the lugs and plates I I and h h, before explained, while toprovide at the upper end of the main sec tion a device to preventseparation of the two sections, and to' guide the extension as it isbeing raised or lowered, I secure to the upper end of the said mainsection cars at m, which overlap the outer surfaces of the rails N N.These ears permit of passage of the trusses 0f the extension as thelatter is being raised or lowered, which would not be the case if a baruniting the two rails of the section was employed. The trusses at thelower end of the extension J of the ladder pass over or are socured tothe outer ends of braces or arms a 12, secured to the lower end of saidextension, while the trusses at the upper end of the main section of theladder are secured to like arms, 0 0, aiiixed to said main section, thetwo pairs of arms being so arranged with respect to each other that as'the extension reaches its highest position the arms interlock and thetrusses of the two sections of the ladder virtually become one, tostiffen the whole.

To one of the lower rounds of the extension J, I pivot a dog, a,composed of two side cars, 1111, united by a cross-bar, q, the width ofthe cars at their lower ends being such as to intercept the rounds ofthe main section of the ladder, and by resting upon some one of suchrounds support the extension as it is raised. As the extension is raisedthe dog passes over each rung in succession of the main ladder and dropsbetween the one last passed and the one above next succeeding, therebyarresting descent of the extension. To hold the dog out of engagementwith the rounds of the main section, when the extension is to belowered, I pivot to the adjacent part of one of the rails N of saidextension a latch, r, in the form of a bell-crank lever. 1y pushing onearm of the latch r beneath one of the ears of the dog the latter isrestrained from engaging the rounds of the main ladder.

The hoisting apparatus, for elevating the extension J upon the mainportion of the ladder,

consists of an endless chain or rope disposed at each side of the mainsection and between its side rails, such endless chain or rope beingsecured at some suitable point to the extension, and passing aboutdriving-pulleys s s, secured to a shaft, I, mounted in the lower part ofthe main ladder, and also about idle-pulleys u u, pivoted to the upperpart of the main sec tion, the shaft 1 being provided with a crank, c,for rotating it. Rotating the shaft t in one direction effects theelevation of the extension upon the main section, while a reversemovement of the shaft allows the extension to lower by its own gravityor, in case of necessity, the shaft and rope may be used to pull theextension part down.

The main windlass, before alluded to, is shown in the drawings ascomposed of a hori zontal drum, 1e,journaled to the upper part of thetruck, and carrying at one end a spur-gear, x, which engages apinion, y,fixed to the adjacent end of a horizontal shaft, 2, also journ aled tothe top of the truck and disposed alongside of and parallel with thedrum, the said shaft carrying at its opposite end a ratchet-wheel, a,which operates with a pawl, I), pivoted to the adjacent part of thetruck-frame to preventfallingof the ladder while it is being raised byand with the swinging standard, or being elevated into a verticalposition after the latter has been brought to an erect position. Ropes cd extend from each end of the drum outward to and are connected with thelower end of the ladder, preferably passing over a horizontal beam, 0,which spans the base of the standard E, and which constitutes one of thepoints of support of the ladder while the latter is in a recumbentposition.

The secondary windlass, before alluded to, is shown as composed of ahorizontal drum, journaled, as shown at g g, to the upright standards 00, before mentioned as erected upon the front part of the truck, a ropeor chain, It, being secured at one end to the drum, and partially coiledabout the latter, and thence extending to and being connected with theextreme outer or upper end of the extension J, onejournal of thedrumfbeingprovidcd with a crank.

The operation of my ladder is as follows, it being supposed that it isin traveling condition, as shown in the drawings: If it is to be used ata burning building, the truck is driven up to the burning building, thehorsrs are removed, and the brake applied to the hind wheels, afterwhich the ladder is set in motion. Two men or more are essential toproperly operate the ladder, and one seizes the crank of the mainwindlass and the other that of the secondary windlass, and the pawl b isdropped into engagement with the teeth of the ratchet-w heel a. By meansofshaftz the drum w is now turned to the left and the standard E raisedto an erect position, the rear end of the ladder being raised with it,while the front end of the ladder rests upon the roller 11. The guy ropeorehain It, being kept constantly taut by the other man, prevents thetendencyof the ladder to slide forward from elevating the standard toosuddenly. The drum to is now turned in the same direction until theladder is rotated upon its pivot i and brought from a recumbent to anupright position, the guy-rope being kept taut during this movement by apawl and ratchet, with which it is provided. The ladder is now availablefor an ordinary height-say fifty feet; but if a greater height is to beattained, the shaft t is to be rotated in the right direction, whichhoists the extension J upon the main section to the desired height; andto alter the an gle of the main ladder the main drum is released fromthe restraint of its pawl, to permit of a less elevation of the mainsection, and returned to place when said section is to be elevated orraised nearer the perpendicular. The guy-ropes, as before stated, serveto prevent swaying of the upper portion of the ladder.

To contract the ladder preparatory to removing it from the place itoccupied, the extension is lowered upon the main section by the rotationof the shaft 25, and the crank of the drum w is again seized, its pawlremoved from ratchet-wheel, and the ladder is allowed to lower by itsown gravity to and upon the roller I), the slack of the guy-rope Itbeing taken up by rotating the drum f in the proper direc tion, it beingobserved that the said guy-rope passes from its drum upward over theroller 0, thence horizontally outward to the end of the ladder. The drumf is now rotated to the right or toward the rear of the truck, and thetension upon its rope forces the ladder rearward until the pointofequilibrium of the standard E is passed, when the standard and ladderdrop together by their combined gravity to a seat upon the rear end ofthe truck, the drum to being restrained from turning rapidly, in orderto prevent too sudden descent of the ladder.

It will be seen that by pivoting the ladder to the swinging standard, asexplained, I am enabled, when the standard is raised, to obtain a veryfirm bearing for the ladder, from the reason that the pivot whichconstitutes the hearing is situated at a considerable distance from thebottom of the ladder, and for the same reason I obtain a long leverageor purchase, by which I am enabled to raise my ladder into an erectposition with little power. At the same time I am enabled by pivotingthe standard to the truck to lower the ladder to the top of such truckwhen it is to be transported.

By the employment of hoisting chains or ropes on both sides the ladderto elevate the extension, in lieu of a single one in the center, as hasheretofore been the case, I am enabled toobtain great, and insure smoothand steady, movement of such extension.

In preparing to erect the ladder I raise and advance the foot of theladder first, which is a considerable. advantage.

By hoisting the extension round by round upon the main section I amenabled to increase the length or height of the ladder to a smallextent, as may be desired, in lieu of increasing its length by theaddition of a whole section.

Although I have described my invention as a ladder, it is evident thatits principle of operation will be applicable to derricks with equaladvantage, and do not restrict myself to a lad der so long as theinvention is applicable to either.

. Having thus explained the naturc,purposes,

and advantages of my invention, I claim and desire to secure by LettersPatent of theUnited States as follows:

1. The combination of the ladder, the truck, and an interveningladder-supporting standard hinged or pivoted to the truck, such standardcarrying the pivotal point of the ladder, and being adapted to raise andlower said ladder with respect. to the truck and before it is elevatedto an erect position, substantially as stated.

2. The combination of the truck, the standard hinged or pivoted to thetruck, the extension-ladder hinged or pivoted to the standard, and themain and secondary windlasses.

3. The two sections of the ladder with their respective trusses adaptedto interlock when the ladder is fully extended and constitutepractically a continuous truss, substantially as stated.

4. The standard hinged to the truck, adapted while in an erect positionto provide a bearing for the ladder at a considerable elevation abovethe truck and the ground, and while in a lowered position to bring theladder as closely as possible to the truck for ease and safety intraveling, substantially as stated.

5. In combination, the hinged standard, the two sections of the ladder,the truck with its elevated roller or bar I), and the secondaryWindlass, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

I JOHN L. CRAFTS.

Witnesses:

H. E. LODGE, F. CURTIS.

